A color image forming method which is most widely used in the field of silver halide color photographic materials includes a method wherein exposed silver halide is allowed to function as an oxidizing agent, and oxidized aromatic primary amine color developing agents react with couplers to form indophenol, indoaniline, indamine, azomethine, phenoxazine, phenazine and analogous dyes. In this system, a method is used wherein a color image is reproduced by subtractive color photography. Generally, a color image is formed by changing the amounts of dyes formed by the three yellow, magenta and cyan colors.
Generally, phenol or naphthol cyan couplers are used to form a cyan dye image. However, since these couplers have undesired absorption in green light region and the blue light region, they have a serious problem in that particularly blue and green color reproducibility is greatly lowered. Accordingly, a solution to this problem is required.
EP 249,453A2 has proposed 2,4-diphenylimidazole cyan couplers to solve this problem. Dyes formed from these couplers show a reduction in undesired absorption in the green light and blue light regions in comparison with conventional dyes and certainly have improved in color reproducibility. However, these couplers are not considered to be fully satisfactory with respect to color reproducibility, and a further improvement is required. In addition, these couplers have serious problems in that the reactivity of these couplers with oxidized developing agents, that is, the coupling activity of these couplers is low, and the fastness of dyes formed to heat and light is quit low. Accordingly, these couplers can not be put to practical use.
JP-A-64-552 (the terms "JP-A" as used herein means an "unexamined published Japanese patent application"), JP-A-64-553, JP-A-64-554, JP-A-64-555, JP-A-64-556 and JP-A-64-557 disclose pyrazoloazole cyan couplers. These couplers show a reduction of undesirable absorption in the green and blue regions in comparison with conventional dyes. However, these couplers have problems in that the color reproducibility is not sufficient and color developability is quite low.
Couplers having a 1H-pyrrolo[1,2-b][1,2,4]triazole mother nucleus are disclosed in a paper (pages 108 to 110) comprising the substance of a lecture at the annual meeting (held May 23 and 24, 1985) of the Photographic Society of Japan, JP-A-62-279340 and JP-A-62-278552. These couplers are known as magenta couplers. The absorption spectra of the dyes, of these pyrrolotriazole couplers described in this 1985 paper of Photographic Society of Japan are slightly broader than those of dyes from well known pyrrolotriazole magenta couplers, and these couplers are not considered to have satisfactory hue as magenta couplers.
Further, JP-A-62-291646 and JP-A-63-32548 disclose couplers with a pyrrolotriazole mother nucleus. However, these couplers are clearly described as magenta couplers, and all of compounds exemplified therein are limited to couplers which form magenta dyes.
Generally, the processing of silver halide color photographic materials comprises a color development stage and a desilvering stage. In the desilvering stage, developed silver formed in the color development stage is oxidized by a bleaching agent having an oxidation effect to form a silver salt (bleaching). The silver salt together with unused silver halide is converted into a soluble silver salt by a fixing agent and is removed from light-sensitive layers (fixing).
Iron(III) ion complex salts (e.g., iron(Ill) complex salts of aminopolycarboxylic acids) are mainly used as bleaching agents, and thiosulfates are usually used as fixing agents.
In one embodiment, bleaching and fixing are separately carried out in a bleaching stage and in a fixing stage, respectively. In another embodiment, bleaching and fixing are simultaneously carried out as a bleaching-fixing stage. The details of these processing stages are described in James, The Theory of Photographic Process, 4th Edition (1977).
Generally, the above-described processing stages are carried out in automatic processors. Particularly, small-size automatic processors comprising miniature laboratories have been provided in shops in recent years, and rapid attention to customers has spread. Since the processors are miniaturized and rapid processing is required, the bleaching agents and the fixing agents are used in the same bath as a bleaching-fixing bath in the processing of color paper.
Rapid processing in the processing stages and easy maintenance have been highly demanded in recent years. High speed-up and the improvement of the stability of processing solutions in the bleaching-fixing stage have been demanded. Further, processing is carried out at various places, and hence a problem in the disposal of waste water in processing has become serious.
Iron(III) complex salts of ethylenediaminetetraacetic acid have been conventionally used in the bleaching stage. In addition thereto, potassium ferricyanide and iron chloride are conventionally known as bleaching agents which have a strong oxidizing power and are capable of achieving rapid bleaching. However, potassium ferricyanide is not widely used form the standpoint of the preservation of environment, and iron chloride can not be widely used from the standpoint of its inconvenience in handling due to metal corrosion. Iron(III) complex salts of 1,3-diaminopropanetetraacetic acid have been proposed as general-purpose bleaching agents with a rapid bleaching effect in recent years. However, when the complex salts are used, bleach fog tends to occur. Hence these complex salts are not considered to be satisfactory bleaching agents.
Thiosulfates used as fixing agents are deteriorated by oxidation and form sulfide precipitates. Accordingly, sulfites are generally added as preservatives to prevent oxidation of thiosulfates. A further improvement in the stability of the processing solutions used is required as replenishment rate is reduced However, when the amounts of the sulfites are increased, a problem with regard to solubility is arises. When the sulfites are oxidized, the precipitate of sodium sulfate is formed. Accordingly, these problems can not be solved. These problems become even more serious with a reduction in the pH of the processing solutions. Further, from the viewpoint of rapid processing it is required that there are developed compounds which are superior in fixing properties to thiosulfates.
When a rapid bleaching-fixing operation is carried out after rapid color development, developing agents, sensitizing dyes and dyes contained in the light-sensitive materials can not be sufficiently removed and stain is formed on images after processing, even though the developing agents, the sensitizing dyes and dyes can be removed in conventional bleaching-fixing stage.
Accordingly, it has been highly desired to develop a fixing agent and a bleaching agent which do not have the above-described problems and to provide a processing composition containing the same and a processing method using the same.
To solve these problems, Japanese Patent Application No. 3-255889 discloses that when a bleaching-fixing solution containing at least one compound selected from the group consisting of nitrogen-containing heterocyclic compounds having a sulfide group, meso-ionic compounds and thioether compounds as fixing agents having excellent stability against oxidation is used in place of thiosulfates, the solution is stable against oxidation, no precipitate is formed when the replenishment rate is low, bleach fog is small in comparison with thiosulfates, and good results can be obtained particularly when bleaching-fixing agents are used in combination with strong oxidizing agents.
When light-sensitive materials containing the above described 1H-pyrrolo[1,2-b][1,2,4]triazote couplers are processed with processing solutions containing thiosulfates as the fixing agents, color reproducibility (color turbidity) can be greatly improved in comparison with the prior art. However, it has been found that when the finished prints are stored under high temperature conditions or under high temperature and humidity conditions, yellow color staining is noticeable because color turbidity is improved, and color reproduction in the low density area is deteriorated. Particularly, in the system wherein rapid processing is contemplated and the replenishment rate of the processing solution is lowered, materials with concerns that colored materials will be formed may be left behind, such materials have a large effect, and stain is markedly formed on images when the processing time is shortened. An adverse effect thereof is observed.
Further, light-sensitive materials are distributed to miniature laboratories and processed there. Where leisurely processing is conducted, it has been found that the fixing agents and silver salts are deposited on light-sensitive material-conveying rollers during the course of leisurely processing. The term "leisurely processing" as used herein refers to the following situations.
(1) The amount of light-sensitive materials processed per day is small, or the processing time is short.
(2) The amount of light-sensitive materials processed per unit time during operation is small.
(3) The interval of time between operations is long. For example, the processing time required for one operation is short (the amount of the material to be processed is small), but the down time is long, or even when working time is long, the down time -until the subsequent operation is long.
When the fixing agents or the silver salts are deposited on the conveying rollers during leisurely processing, the deposits are transferred onto the light-sensitive materials, whereby the light-sensitive materials are stained. Accordingly, the conveying rollers must be frequently cleaned.